Experimental and Numerical Study of Fracture Behavior of Rock-Like Material Specimens with Single Pre-Set Joint under Dynamic Loading

The Split Hopkinson Pressure Bar (SHPB) is an apparatus for testing the dynamic stress-strain response of cement mortar specimen with pre-set joints at different angles to explore influence joint attitudes underground rock engineering on failure characteristics mass structure. nuclear magnetic resonance (NMR) has also been used measure pore distribution and internal cracks before after testing. In combination numerical analysis, paper systematically discusses mode rock-like materials from three aspects energy dissipation, microscopic damage, stress field characteristics. result indicates that impact structure SHPB greatly affected by angle specimen. With increasing, proportion reflected moves in fluctuation, while ratio transmitted dissipated varies one other. NMR analysis reveals structural variation pores those specimens impact. Crack propagation direction correlated specimens. increase angles, crack initiation decreases gradually. When are around 30°–75°, develop obvious cracks. crushing process simulated LS-DYNA software. It concluded stresses time concentrated between 20 40 MPa. instantaneous curve first increases then propagation, peaking times under various angles; but most them occur when penetration reaches 80–90%. increment through simulation software, changing trend peak consistent test results.